Texas/Oklahoma 2023 Obs and Discussion

[Powerball]

And not to be neglected, new Record Maximum Lows of 79*F were also set at DFW yesterday and today.

[Castaway]

I’m in Oklahoma City for a bit. Was watching a nice tower form to the east and went severe warned. 
 

Hot day around 95

[cheese007]

Beautiful supercell on the TX Storm Chaser YouTube live feed

[Powerball]

There's a good chance DFW will hit 100*F again today.

After today, we'll be 1 day short of tying 1998 for the 3rd most 100*F+ days in a year, and surpass 2000 for the most 100*F+ days in September.

EDIT: Depending on the evolution of convection throughout the day, today may be the latest 80*F+ low ever observed in the season as well.

[Powerball]

Dallas = New LA...

https://www.keranews.org/energy-environment/2023-09-22/new-tool-says-dallas-fort-worth-ranks-third-in-the-world-for-transportation-related-greenhouse-gas-emissions

[Ed, snow and hurricane fan]

Area of storms that on current trend will miss Houston metro to the E.  CAPE is sufficient, a bit of backbuilding W wouldn't be surprising.  And then whatever comes down this evening/tonight from the North and Central Texas SPC outlooked storms.

 

7 day GFS ensemble rain total for my house (and on down into STX) is just under half an inch.  Hit and miss nature of recent rain suggests fire danger still exists.

[Powerball]

Just got a bunch of fat raindrops for about 30 seconds. Was enough to dampen the ground and make a few puddles.

Fortunately, most of this weak sauce crap percolating seems to missing the airport, so another 100*F high should still be on the table.

[Ed, snow and hurricane fan]

19 minutes ago, Stx_Thunder said:

MCD out for North/Central TX region:

https://www.spc.noaa.gov/products/md/md2192.html

 

 

CAM runs today and this time are in good agreement with the North/Central TX convective initiation by this evening. So it explains why SPC is holding firm on the large SLGT risk area through tonight.

Will be interesting how the likely MCS evolves/progresses south toward the southern/eastern half of the state tonight/Monday morning given the already sufficient mid-upper level dynamics in place (Effective Shear already around 35 kts, and MMP value around 50% in STX on 12z CRP sounding today). As the High has just started its significant moving away from the state trend just in the past day or two.

NASCAR doesn't draw the crowds it used to at TMS, on the Wise/Denton County border.  (Part of Fort Worth, even though not in Tarrant County).  Still, probably >50.000 people at an outdoor sporting event.  I wonder what hail would do to the race cars.

[Powerball]

For what little it's worth. Radar/satellite look quite underwhelming thus far...

 

[Powerball]

In the mean time, DFW made it to 101*F for the 2nd day in a row, another record...

[cstrunk]

Getting more interesting now, including a tornado warned storm near Commerce, TX.

[Chinook]

There have been several large hail reports of 1.5" + today in northern Texas. As for this, I do not know if there was a confirmed tornado at Commerce, TX

 

[Powerball]

It's finally my turn. Ton of CTG lightning.

[Powerball]

8 hours ago, Powerball said:

It's finally my turn. Ton of CTG lightning.

Ending uo getting no more rain more other than the 30s seconds of fat raindrops from earlier yesterday afternoon.

[Powerball]

Welp, the 80s that were in the forecast went POOF.

But we seem to be finally done with the 100s, lol...

[Powerball]

In all likelihood, this September will end up being the 2nd warmest on record for DFW.

Only September 2019 was warmer.

[Ed, snow and hurricane fan]

Monday was wind and thunder and power out, Tuesday looked to be dry with big storms to the E, but they made it here around 7 pm.  Severe warned, but just a nice rain with a little thunder.  Maybe turning the corner on the drought.  Warmer than normal doesn't look to change.

[Ed, snow and hurricane fan]

Autumn is finally coming.

[Ed, snow and hurricane fan]

Extra zero in 15000, and my house is only marginal, but the front Thursday looks to be a wet one as well

 

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
429 AM EDT Tue Oct 03 2023
 
Day 1
Valid 12Z Tue Oct 03 2023 - 12Z Wed Oct 04 2023 

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF 
THE TEXAS COAST...


...Texas Coast...

Southeasterly flow from the Gulf of Mexico will interact with a 
coastal trough to produce showers and thunderstorms this afternoon 
and early evening. Heavy rainfall is possible within the Slight 
Risk area, between Houston and Corpus Christi this afternoon, when 
instability will be at its peak (1000-15000J/Kg). There will be 
plenty of moisture present, despite the lack of dynamic support, 
with PWATs between 2-2.5" along the Texas coast. HREF neighborhood 
exceedance probabilities of 2-5" are reasonably high at this time 
so those were used as a proxy for this day 1 Slight Risk area.

[Powerball]

21 minutes ago, Stx_Thunder said:

 

- SPC finally getting their act together. Wouldn't be surprised if they expand that enhanced risk into or near the DFW area this afternoon due to more significant damaging wind gusts or hail events (given the upward of 60 kt shear CAMs are showing in that region by this evening).

Probably a good mid-level shortwave coming into the mix too given how deep that incoming upper level trough probably is also. Can't really underestimate these EN Fall systems. Especially being still pretty early in the season.

Not going to happen due to less than ideal timing (late evening hours) and already somewhat marginal instability with an unimpressive dewpoint/temp spread, likely preventing much of that shear from mixing down to the surface.

The enhanced risk is mainly for very large hail (2-3"+) with the initial activity.

[Powerball]

9 minutes ago, Stx_Thunder said:

Despite the lower CAPE on this morning's sounding, I wouldn't say that's marginal instability up there in DFW given the already fairly weak inhibition, 700mb - 500mb lapse rates already up at 7 C, a 70 F + surface dew point (which I would think is pretty high for this time of year up there in October), and already almost 35 kts Effective shear, and nearing 100 kts cloud shear now.

And, the forecast of no real MLCINH on CAMs around there through the evening.

Craven/Brooks SigSevere already at 20,000 also. Which will likely increase through the day just like the shear values with the upper trough obviously getting closer. BRN low, but will probably go up later today with lower-level flow veering and increasing from the south-southeast.

Plus, 12Z CAM runs like the ARWs this morning are pushing back on the main and pretty sharp convective line further into the evening compared to yesterday evening runs. This could be an indication of the upper trough deepening/slowing down.

--- 
At this point, it looks like a close call looking at the latest data and parameters this morning as more would seem to favor it later today than not (despite it being a nocturnal event).

Especially if there's a potent incoming mid-level shortwave involved (like SPC is talking about today). If there isn't or timing is off with the stronger dynamics coming in this evening, then severe would be less likely around there.

To clarify, the reason I say somewhat marginal instability for severe weather is because much of that instability on the sounding you presented is elevated. Even the CAMs indicate a stable layer forming near the surface by the time the storms arrive into DFW (temps only in the low 80s and dewpoints in the low/mid 70s), which will significantly temper downburst potential.

Instability and moisture levels are definitely good enough for prolific rain producers and frequent lightning though, which is already pretty well covered in the current outlooks/forecasts.

[Powerball]

30 minutes ago, Stx_Thunder said:

MUCAPE this morning is at 990mb. Which is literally just above the surface layer...

I would in no way, consider that elevated.

Even with a stable near surface layer, if you have enough deep-layer or effective shear and support for lift going on aloft with a relatively unstable boundary layer, it can still promote stronger cells and higher wind gusts. Especially in a very linearly forced MCS or segment.

Since you replied toward me, the only other thing I'm going to add is SPC, especially on updated Day 1 outlooks, would not be highlighting your area in a large Slight risk if they knew the severe potential wasn't actually there. And, they've pretty much explained their reasoning with just about everything I wrote about the ongoing convective parameters in here. It's not just about what the conditions are at or near the surface (or how unstable/stable it is in that layer alone in your case). Elevated supercells also do actually exist.

On the contrary, from all my convective analysis experience over the years, it has a lot more to do with the boundary layer when it comes to instability. And even with limited instability overall, it still does not mean severe can't happen at all (and has before). Even SPC talks a lot about all of these things too, reading their discussions frequently over the years.

Also, they've expanded the enhanced risk area much closer to you now in the late morning update.

 

The severe threat is definitely there. I just disagree that it's great enough for an upgrade to an enhanced risk (as you seem to) for DFW.

The better potential will be NW of here, where the activity will occur during or just after peak heating.

[cheese007]

Tornado Warning
TXC113-139-050330-
/O.NEW.KFWD.TO.W.0066.231005T0242Z-231005T0330Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Fort Worth TX
942 PM CDT Wed Oct 4 2023

The National Weather Service in Fort Worth has issued a

* Tornado Warning for...
  Northwestern Ellis County in north central Texas...
  Southern Dallas County in north central Texas...

* Until 1030 PM CDT.

* At 942 PM CDT, a severe thunderstorm capable of producing a tornado
  was located over Midlothian, moving east at 30 mph.

  HAZARD...Tornado and half dollar size hail.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without
           shelter. Mobile homes will be damaged or destroyed.
           Damage to roofs, windows, and vehicles will occur.  Tree
           damage is likely.

* This dangerous storm will be near...
  Cedar Hill and Midlothian around 950 PM CDT.
  Waxahachie, Ovilla and Oak Leaf around 955 PM CDT.
  Glenn Heights and Red Oak around 1000 PM CDT.
  Ennis around 1015 PM CDT.
  Palmer around 1020 PM CDT.

Other locations impacted by this tornadic thunderstorm include Ike,
Garrett, Trumbull, Pecan Hill, Boyce, Rockett, India and Joe Pool
Lake.

This includes the following highways...
 Interstate 35E between mile markers 399 and 414.
 Interstate 45 between mile markers 251 and 270.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to an interior room on the lowest floor of a
sturdy building. Avoid windows. If you are outdoors, in a mobile
home, or in a vehicle, move to the closest substantial shelter and
protect yourself from flying debris.

Tornadoes are extremely difficult to see and confirm at night. Do not
wait to see or hear the tornado. TAKE COVER NOW!

&&

LAT...LON 3232 9661 3242 9709 3243 9709 3251 9708
      3255 9704 3258 9704 3261 9656
TIME...MOT...LOC 0242Z 283DEG 25KT 3250 9704

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.25 IN

$$

Bonnette

[Chinook]

Wow! That might be a TDS confirmed tornado at Britton Texas, near Midlothian. I thought this severe event might be over.

 

[nwohweather]

7 minutes ago, Chinook said:

Wow! That might be a TDS confirmed tornado at Britton Texas, near Midlothian. I thought this severe event might be over.

 

Exactly my thoughts! The spin and inflow are pretty legit on this thing. We have a large plant in Midlothian so definitely watching with curiosity 

[Chinook]

The northeast side of Dallas may have gotten 2.5"-3" at this point in time. I have not seen a report of a tornado.

[Powerball]

1 hour ago, Stx_Thunder said:

 

- Bulk shear was nearing 50 kts (like the 12Z CAMs were showing by evening), effective shear nearing 60 kts, and Significant Severe value was passing 50 K at the time of the 0Z FWD sounding launch tonight, with virtually nil CIN of any kind.

Moisture was lacking a little with 60% RH in both lower and mid levels. So the boundary layer wasn't quite unstable as the lower to mid-level lapse rates dropped some during the day.

Outflow or frontal boundary also outran the storms as I saw on radar going through DFW which cut off some of the boundary layer or southerly lower level inflow into the cells. Had they not been undercut by the boundary, things would've likely been a bit more interesting severe-wise all around there.

Overall, it was a sufficient enough potential to justify the enhanced severe risk around DFW area with all the severe instances and warnings issued around there a while after dark, also taken into account.

Especially, the convective segment with 75+ mph measured gusts that literally came right next to Fort Worth metro as I also saw on base velocity next to 9:00 PM from the west.

 

Only 3 confirmed reports so far in DFW.

Granted, there may be more forthcoming, but in all likelihood still not enough to be enhanced risk worthy IMO.

Aside from that overachieving mini-bow echo that moved into FW proper (and actually weakened shorty thereafter), it's been largely "more bark than bite" severe-wise, with impressive shear on paper that didn't translate into a more impressive event. And that's pretty typical for these nighttime events in the Fall, which is why I didn't really buy into the hype.

That being said, it's certainly been a solid event rain-wise for the Metroplex and has been a prolific lightning producer.

[Powerball]

Also, I will say, I did see widespread observations of wind gusts in the 35-45 MPH range, which (although sub-severe) is something.

And that was likely in part due to the somewhat lower than expected RH levels mentioned, as that helped to enhance the downdrafts a bit (though still not enough to overcome the cooling boundary layer).

[Ed, snow and hurricane fan]

Nothing severe, but decent MCS an hour from Houston, morning commute will be interesting.

[cstrunk]

2.7" storm event total since yesterday morning.